• Title/Summary/Keyword: equidistance

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ANALYSIS OF THE KOREAN CELESTIAL PLANISPHERE: CH'ON-SANG-YUL-CHA-BUN-YA-JI-DO

  • PARK CHANGBOM
    • Journal of The Korean Astronomical Society
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    • v.29 no.spc1
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    • pp.433-437
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    • 1996
  • We have analyzed the content of the Korean stone star chart. Ch'on-Sang-Yul-Cha-Bun-Ya-Ji-Do(here-after Ch'on-Sang-Do). In the star map we have found 1468 stars, 4 more than the Chinese star catalog Bo-Chun-Ga. The four extra stars form a constellation, Jong Dae Boo. The map projection law used in the star chart is found to be the polar equtorial and equidistance projection. The linear distance of an object on Ch'on-Sang-Do from the center is linearly proportional to the north polar angular distance. We have found from a statistical analysis that most stars with declination lower than 50 are at positions representing the epoch of around the first century. On the other hand, stars near the north pole with declination higher than 50 are at the epoch of about 1300, which is close to the time the chart was engraved. This implies that the original Ko-Gu-Rye Dynasty's star chart has been revised by astronomers of Cho-Sun Dynasty. We have also shown that stars on Ch'on-Sang-Do are engraved in such a way that their area is linearly proportional to the visual magnitude.

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An Energy-Efficient Multi-Hop Scheme Based on Cooperative MIMO for Wireless Sensor Networks

  • Peng, Yu-Yang;Abn, Seong-Beom;Pan, Jae-Kyung
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.36 no.9A
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    • pp.796-800
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    • 2011
  • An energy-efficient multi-hop scheme based on cooperative MIMO (multiple-input multiple-output) technique is proposed for wireless sensor networks, taking into consideration the modulation constellation size, transmission distance, and extra training overhead requirement. The scheme saves energy by selecting the hop length. In order to evaluate the performance of the proposed scheme, a detailed analysis of the energy and delay efficiencies in the proposed scheme compared with the equidistance scheme is presented. Results from numerical experiments indicate that by use of the proposed scheme significant savings in terms of total energy cousumption can be achieved.

Color gamut mapping using fictive 3-D CIELAB equidistance sample (가상의 3차원 CIELAB 등거리 색표본을 이용한 색역사상)

  • 오현수;곽한봉;이철희;서봉우;안석출
    • Journal of the Korean Graphic Arts Communication Society
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    • v.19 no.2
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    • pp.58-67
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    • 2001
  • Gamut mapping is a technique that acts on cross-media color reproduction to transform a color between devices for the purpose of enhancing the appearance or preserving the appearance of an image. Gamut mapping essentially produces color conversion error which depends the gamut mapping method, source and destination devices, and sample points for gamut modeling. For color space conversion between monitor colors and printer colors, empirical representation using sample measurements is currently widely utilized. Color samples are uniformly selected in the device space such as CMY or RGB, represented as color patches, and then measured. However, in the case of printer, these color samples are not evenly distributed inside the printer gamut and the color conversion error is increased. Accordingly, this paper introduces a equally distributed color sampling method in CIELAB space, a device- independent color space, to reduce color conversion error, and the performance is analyzed via color space conversion experiments using tetrahedral interpolation.

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Comparative Performance of the Size Determination Method Using Quality Loss Function (품질손실함수를 이용한 규격치 결정방법의 성능평가)

  • Lim, Sung-Uk;Kang, Hyoun-Jung;Park, Young-Taek
    • Journal of Korean Society for Quality Management
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    • v.38 no.4
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    • pp.587-592
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    • 2010
  • This paper deals with the performance evaluation of determining production size specifications. A customer who does not find the size specification he or she wants may purchase rather a larger or smaller one, but the purchasing desire decreases as the difference between the required and the prepared sizes increases. Introducing a generalized quality loss function which reflects how much the purchasing desire changes according to the difference, Park and Kim(1992) formulated a mathematical model for determining the size specifications so as to minimize the expected loss. Afterward the model has been applied to the determination of sizing system for mail order clothing and brassiere (Lee and Choi, 1996; Chun, et.al., 1996). The performance of the size determination method proposed by Park and Kim is evaluated in this paper. Usually the intervals between two successive size specifications are determined to be equal, but the size determination method compares favorably with the equidistance case, and more favorably if the population distribution is more skewed.

Conversion of Fisheye Image to Perspective Image Using Nonlinear Scaling Function (비선형 스케일링 함수를 이용한 어안 영상의 원근 변환)

  • Kim, Tae-Woo;Cho, Tae-Kyung
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.10 no.1
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    • pp.117-121
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    • 2009
  • The fisheye image acquired with a fisheye camera has wider field of view than a general use camera. But large distortion of the object in the image requires conversion of the fisheye image to the perspective image because of user's difficult perception. The existing Ishii's method[1] has the problem that the object can has sire and geometrical distortion in the transformed image because it uses equidistance projection. This paper presented a conversion technique of the fisheye image to the perspective image using sealing function. In the experiments, it was shown that our method reduced size and geometrical distortion by applying the scaling function.

The Role of Geological and Geomorphological Factors in the Delimitation of Maritime Boundaries (해양경계획정에서 지질 및 지형적 요소의 효과에 관한 고찰)

  • Yang, Hee-Cheol;Park, Seong-Wook;Jeong, Hyeon-Su;Yi, Hi-Il
    • Ocean and Polar Research
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    • v.29 no.1
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    • pp.55-67
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    • 2007
  • A reference to natural prolongation appeared for the first time in the North Sea Judgement. Although it was not suggested that the concept of natural prolongation would automatically allow for the fixing of a continental shelf boundary, that concept encouraged States to request international tribunals to determine continental shelf boundaries on the basis of the geological and geomorphological features of the seabed. In the Libya v. Malta Case, however, the rejection of geological and geomorphological factors was total. Especially, Natural prolongation was the then checkmated as a relevant fact in delimitation between coasts situated less than 400 nm. apart. There can be no doubt that, in several disputed cases, prominent geomorphological variations are simply ignored ; nevertheless, there are also a few agreements where geological and geomorphological characteristics come into play and, to a certain extent, affect maritime boundaries. Physical characteristics of sea-bed are generally given serious consideration in the boundary delimitation such as the final negotiated boundary of the Australia-Indonesia Continental Shelf boundary Agreement(Timor and Arafura seas) which follows the continental slope bordering the Timor Trench.

Performance Characteristics of Subband Adaptive Array Antenna using Kalman Algorithm (Kalman 알고리즘에 의한 대역분할. 합성형 어댑티브 어레이 안테나의 동작 특성)

  • 박재성;오경석;주창복;박남천;정주수
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.3 no.3
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    • pp.501-507
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    • 1999
  • At the mobile unit for adaptation the propagation environment, it is necessity to adapt very fast the weight coefficient vector of adaptive array antenna In this paper, for the BPSK and BFSK signals with S/I=2, S/N=10 subband adaptive array signal processing method to the linear array antenna using the LMS & the Kalman filter algorithm is proposed. For the 4 elements equidistance linear array antenna systems LMS and Kalman algorithms with subband adaptive instruction principles using the subband signal processing method are adopted and the computer simulation results to the constant amplitude envelope signals such as BPSK or BFSK can be seen that the convergence characteristics of directional patterns and the signal following characteristics are more fast and stable.

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A Study on the Maritime Delimitation Policy of China on Maritime Delimitation in Tonkin Gulf and Policy of Korea (통킹만 경계획정을 통해본 중국의 해양경계획정 정책 및 우리나라 대응방안에 관한 연구)

  • Yang, Hee-Cheol;Park, Seong-Wook;Jeong, Hyeon-Su
    • Ocean and Polar Research
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    • v.29 no.3
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    • pp.245-262
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    • 2007
  • On 25 December 2000, China and Vietnam signed the Agreement on the Delimitation of the Territorial Seas, EEZs and Continental Shelves in the Tonkin Gulf. Three and a half years after signature, in June 2004, China and Vietnam both ratified a maritime boundary agreement for the Tonkin Gulf (Beibu Gulf) and the agreement entered into force. A potentially complicating factor in the negotiation process was likely to have been the status of the Sino-French Agreement of 1887. In the end, the agreement reached indicated that even if the status of the Sino-French Agreement of 1887 was part of the negotiations, both sides eventually agreed that it would not have an impact on the delimitation of maritime zones in the Gulf of Tonkin. Another crucial issue was the impact of the islands, in particular, the Vietnamese controlled Bach Long Vi Island and Con Co Island. Especially, Bach Long Vi Island was entitled to a half suite of maritime zones (3n.m. EEZ) and would impact the tracing of a line of equidistance in the Gulf of Tonkin. Minor as the point might be, Con Co Island also would have an impact for it would play a fixing terminal point for the boundary. Article 7 of the agreement is about minerals and hydrocarbons of cross-boundary deposit, and if any single geophysical structure of oil and gas or other mineral deposits should straddle the demarcation line, an agreement is to be reached on the development of the structure or deposit and on the most effective manner to equally share the profits resulting from the development.

Geographical Study on the Boundary Dispute of Ieodo Sea between Korea and China (한.중 간 이어도해(海) 영유권(領有權)분쟁에 관한 지리학적 고찰)

  • Song, Sung-Dae
    • Journal of the Korean Geographical Society
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    • v.45 no.3
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    • pp.414-429
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    • 2010
  • With regard to Ieodo, South Korea and China argue that Ieodo belongs to their territory respectively, considering its history. However, both parties haven't suggested concrete evidence to support their argument. Even if they suggest corroborative facts, they are distorted or exaggerated like myth. Therefore, it is important by what side primitive title and effective control are exercised in settling the problem of Ieodo. The issue was to suggest coherence logic by finding concrete geographical facts in the East China Seat the time of applying a method of boundary decision followed by the marine act, namely principle of median line and principle of equidistance. China has argued that China should occupy most of continental shelf in the East China Sea on the basis of silt, a deposit of the continent. However, the base of the East China Sea is a part of Eurasian Plate. In addition, a geographical contribution to formation of the continent shelf by the Korean Peninsula is equal to the Chinese Continent. Ieodo is 'Island of mythos' in China, but is 'Island of legend' suggested by concrete facts in South Korea. Therefore, its cultural titile and primitive title are belonged to South Korea, before its historical title.

The impact of beam angle configuration of intensity-modulated radiotherapy in the hepatocellular carcinoma

  • Kim, Sung Hoon;Kang, Min Kyu;Yea, Ji Woon;Kim, Sung Kyu;Choi, Ji Hoon;Oh, Se An
    • Radiation Oncology Journal
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    • v.30 no.3
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    • pp.146-151
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    • 2012
  • Purpose: This treatment planning study was undertaken to evaluate the impact of beam angle configuration of intensity-modulated radiotherapy (IMRT) on the dose of the normal liver in hepatocellular carcinoma (HCC). Materials and Methods: The computed tomography datasets of 25 patients treated with IMRT for HCC were selected. Two IMRT plans using five beams were made in each patient; beams with equidistance of $72^{\circ}$ (Plan I), and beams with a $30^{\circ}$ angle of separation entering the body near the tumor (Plan II). Both plans were generated using the same constraints in each patient. Conformity index (CI), homogeneity index (HI), gamma index, mean dose of the normal liver (Dmean_NL), Dmean_NL difference between the two plans, and percentage normal liver volumes receiving at least 10, 20, and 30 Gy (V10, V20, and V30) were evaluated and compared. Results: Dmean_NL, V10, and V20 were significantly better for Plan II. The Dmean_NL was significantly lower for peripheral (p = 0.001) and central tumors (p = 0.034). Dmean_NL differences between the two plans increased in proportion to gross tumor volume to normal liver volume ratios (p = 0.002). CI, HI, and gamma indices were not significantly different for the two plans. Conclusion: The IMRT plan based on beams with narrow separations reduced the irradiated dose of the normal liver, which would allow radiation dose escalation for HCC.